Drain water, which is frequently laden with trash, grass clippings, tree leaves and stems, sand, gravel, and other forms of sediment, is collected from streets, parking lots and other areas into a storm drain inlet where it is directed into a storm water drain pipe system. The drain water laden with trash, leaves, grass clippings, sand and gravel collected from the streets is fed through an entrance into a storm water catch basin and into a lake or retention pond. The retention pond can tolerate a certain amount of grass clippings and leaves collected from parking lots or along the street but debris left in the water for a long period of time decays and allows a buildup of soluble nutrients, such as nitrates and phosphates, to accumulate in the water. Thus, it is desirable to remove organic debris from the water collected from the drain water before it enters into lakes and retention ponds.
The present filter basket is added directly to the storm water drain pipe system for collecting trash, leaves, grass clippings, tree stems, and other organic matter in a manner to dry these materials before they can rot in the water and release soluble nutrients into the water. Sand, gravel, or other non-organic sediments can pass through the basket screen walls and are collected within a drain water catch basin. The present system provides for an easily cleaned filter basket which allows rapid cleaning of the filter basket and filter box in situ.
In rivers and other bodies of water, such as lakes and ponds, the groundwater levels vary on a seasonal basis so that the nutrient separating baffle box has to have a screened basket which should ideally be kept at 3-4″ above the water level for optimum performance. Nutrient separating filter baskets, however, are normally fixed in position within a storm water drain system. The baffle box can be adjusted as to height with great difficulty.
The present invention provides for an easy and rapid adjustable filter basket which can be rapidly adjusted for ground water level and the water entering the storm water drain baffle box.
In my prior U.S. Pat. No. 6,428,692 for an In-Line Storm Water Drain Filter System an in-line storm water drain filter and baffle box is installed within a storm water drain pipe to direct storm water runoff through the storm water drain pipe and through the filter and baffle box prior to the storm water drain water passing through an outfall into a lake, pond or retention area. This patent is for a filter system and includes a housing having an inlet and outlet and a plurality of chambers formed therein. The housing cover allows for access into a housing. A plurality of filter screens are mounted over each of the plurality of housing chambers for collecting trash from the storm water passing therethrough.
In my prior U.S. Pat. No. 7,270,747, I provide a storm water drain system having a nutrient separating filter basket installed within the storm water pipe system to receive storm water runoff therethrough and to collect organic materials, such as grass clippings, leaves, and tree stems. The filter basket in the storm water drain has a rigid frame and a plurality of screen sides in the top and bottom and open front end attached to the interior wall edges. An inlet feed chute attached to the filter basket open front end is positioned in front of the storm water housing inlet for directing storm water and debris into the filter basket. The water entering the housing inlet is directed by the inlet feed chute into the basket and through the screen sides and bottom while the filter basket is collecting the organic debris therein.
The present invention is an improvement to this prior U.S. patent and allows a screened filter basket to be readily adjustable to receive the inflow of storm water for different water levels entering a baffle and separating box for collecting the larger debris within the screen basket.